A gear formed by a forging process has pads projecting at least to a pressurized side surface. A cutting process is applied to the side surface in order to cut off the projecting part of the pads.
A weld flash occurs on an elongation of cut surface of tooth surfaces on the gear owing to the cutting process. Generally chamfering is carried out to a corner part in order to finish the corner part having the weld flash and this chamfering has been carried out by cutting.
A cutting process inherently has problems such as the attrition of tools, occurrence of chips, difficulty of forming optional forms and requiring long machining time. Particularly, chamfering must be carried out one tooth at a time by turns. Therefore, chamfering is inefficient and needs an appreciable amount of time.
Furthermore, when chamfering is carried out by cutting process in order to remove a weld flash generated by cutting side surface, a new weld flash can occur due to the chamfering.
A process yield is influenced on a large scale by the occurrence of weld flash and a step of screening defective products having weld flash was required.